POS1176 HOSPITALIZATION RATES, FEATURES, AND DISCHARGE DIAGNOSES OF A LARGE NATIONWIDE COHORT OF ANCA-ASSOCIATED VASCULITIS
Authors: A. Berti, M. Ottone, S. Sartorelli, E. Treppo, A. Bettiol, R. Padoan, F. Regola, S. Monti, C. Marvisi, A. Giollo, L. M. Argolini, M. Righini, A. Gattamelata, G. Cassone, L. Sottini, M. Maule, P. Toniati, B. L. Palermo, F. Bello, S. Guella, R. Izzo, F. Muratore, M. G. Catanoso, A. Fassio, P. Cataleta, A. Buscaroli, P. Giorgi Rossi, F. Franceschini, R. Caporali, C. Montecucco, F. Conti, G. Emmi, L. Quartuccio, G. Paolazzi, L. Dagna, F. Schiavon, C. Salvarani, R. Bortolotti
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Hospitalizations due to relapse or disease complications are major concerns during follow-up of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). <h3>Objectives</h3> To determine rates of hospitalization in a large cohort of patients with AAV compared with the national general population, and to describe features and associated primary discharge diagnoses. <h3>Methods</h3> Between 2007 and 2018, we examined the hospitalization records of AAV patients from 13 Italian hospitals. Hospitalization dates, features, length of stay, primary discharge diagnoses and patient data were abstracted from charts. Age- and sex-standardized hospitalization rates (SHR) were calculated by an indirect method, per year and for the study period, using the 2007–2018 hospitalization data provided by the Italian Ministry of Health. Multivariable and survival models were used to explore associations between these outcomes, clinical parameters at diagnosis, and pre-existing comorbidities. <h3>Results</h3> A total of 610 hospitalizations occurred in 635 patients with AAV (19.4% microscopic polyangiitis, MPA; 34.6% granulomatosis with polyangiitis, GPA; 46.0% eosinophilic GPA, EGPA) during a 12-year observation; in 19.8% for life-threatening conditions and leading to death in 2.3%. The median time to first hospitalization was 504 days (25-75%IQR, 95-1497), and the median hospitalization length was 8 days (25-75%IQR, 8-14). The 2018 SHR (95%CI) was 1.14 (0.91, 1.43) for all AAV combined, 1.13 (0.68, 1.76) for MPA, 1.48 (1.02, 2.08) for GPA, and 0.90 (0.60, 1.31) for EGPA. These rates tended to a gradual increase from 2007 to 2018 in the whole AAV cohort of patients and in every disease subset (Figure 1A). The main causes of hospitalization in patients with AAV were infectious diseases (18.7%), followed by major relapse and diagnostic re-evaluation (17.2% each), and cardiovascular diseases (10.8%). Among those due to infections, the main site was the respiratory system (44.6%), followed by urinary tract (9.6%) and sepsis (6.3%). Among AAV patients hospitalized during follow-up (47.1%), 55.5% had only 1 hospitalization, 18.7% had 2, and 25.6% had 3 or more hospitalizations. Patients with a diagnosis of GPA or MPA (versus EGPA), higher vasculitis activity (assessed by BVAS), ANCA positivity at diagnosis, and hospitalization at diagnosis (all p&lt;0.001), more pre-existing comorbidities and older age (both p&lt;0.05), were more likely to be hospitalized during follow-up (Figure 1B). <h3>Conclusion</h3> Patients with AAV have a significant burden of hospitalization during the disease course. Approximately half of the patients is hospitalized during follow-up, with infections, relapses and cardiovascular diseases as the main causes of hospitalizations. Our findings showed the existence of risk profiles of patients more likely to be hospitalized, requiring more active vigilance. <h3>References</h3> [1]Wallace, Z. et al. 'Nationwide Trends in Hospitalizations and In-Hospital Mortality of Granulomatosis with Polyangiitis', Arthritis Care Res. 2016 [2]Mohammad, AJ et al. Severe Infection in Antineutrophil Cytoplasmic Antibody-associated Vasculitis. The Journal of Rheumatology, 2017 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Alvise Berti Speakers bureau: GSK, Marta Ottone: None declared, Silvia Sartorelli Employee of: S. Sartorelli worked at the IRCCS San Raffaele Scientific Institute and San Raffaele University at the time of the study and is now an employee of Bristol Myers Squibb., Elena Treppo: None declared, Alessandra Bettiol: None declared, Roberto Padoan: None declared, Francesca Regola: None declared, Sara Monti: None declared, Chiara Marvisi: None declared, Alessandro Giollo: None declared, Lorenza Maria Argolini: None declared, Matteo Righini: None declared, angelica gattamelata: None declared, Giulia Cassone: None declared, Laura Sottini: None declared, Matteo Maule: None declared, Paola Toniati: None declared, Bianca Lucia Palermo: None declared, Federica Bello: None declared, Silvia Guella: None declared, raffaella izzo: None declared, Francesco Muratore: None declared, Maria Grazia Catanoso: None declared, Angelo Fassio: None declared, Pierluigi Cataleta: None declared, Andrea Buscaroli: None declared, Paolo Giorgi Rossi: None declared, Franco Franceschini: None declared, Roberto Caporali Speakers bureau: AbbVie, Amgen, BMS, Celltrion, Fresenius, Galapagos, Janssen, Lilly, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Fresenius, Galapagos, Lilly, Novartis, Pfizer, and UCB, Carlomaurizio Montecucco: None declared, Fabrizio Conti: None declared, Giacomo Emmi: None declared, Luca Quartuccio: None declared, Giuseppe Paolazzi: None declared, Lorenzo Dagna: None declared, Franco Schiavon: None declared, Carlo Salvarani: None declared, Roberto Bortolotti: None declared.